The invention relates to an internal-combustion engine according to the features of the preamble of claim 1. Internal-combustion engines with a so-called wet-sump lubrication, in which the lubricating oil is returned from the cylinder-head housing and the crankcase to an oil sump situated below the crankcase are known prior art. In order that the lubricating oil should be returned to the oil sump as desired, it is known from the U.S. Pat. No. 5,452,692 for example to provide the crankcase in the region of the rotating crankshaft webs with so-called oil planes which wipe off the lubricating oil taken up by the rotation of the crankshaft, so that the oil can be conveyed to the oil sump by way of return openings as desired. For a continuous and reliable supply of lubricating oil it is necessary for the lubricating oil to be returned rapidly and de-foamed from the crank space to the oil-collecting chamber formed by the oil sump.
The object of the invention is therefore to improve the lubricating-oil circuit for a wet-sump lubrication of an internal-combustion engine so that the lubricating oil is returned rapidly from the consumer devices to the central oil-collection point situated below the crank-case.
This object is attained by the characterizing features of claim 1.
As a result of the wall portion of the crankcase which is designed as an oil plane and which is adapted to the outline of the enveloping curves of the crankshaft webs and/or the big ends of the connecting rods. the greater part of the oil taken up by these rotating, parts is separated and can thus be returned rapidly and on a direct path to the oil sump or the oil-collection point.
Further advantageous embodiments of the internal-combustion engine according to the invention are set out in the Sub-Claims.
Because of the oil-separating chamber which is situated behind the wall portion acting as an oil plane, the separated lubricating oil can be partially de-foamed even before it passes to the oil sump by way of the return openings provided in the oil-separating chamber and by way of an oil deflector. The return openings provided in the oil-separating chamber are used at the same time for the ventilation of the residual gases which are present in the oil sump and which can escape to the outside by way of ducts provided in the crankcase.
The oil-separating chamber situated behind the oil-plane wall portion is provided on the side with oil-return openings which lead to a lateral chamber of the crankcase. The rotor of a generator, which is fastened to the crankshaft flange and the rotation of which assists the return of the oil to the oil-collecting chamber, is arranged in this lateral chamber of the crankcase.
In a manner similar to the wall portion designed as an oil plane in the region of the crankshaft the part of the crankcase adjacent to a balancing shaft is likewise provided with a wall portion, the outline of which is adapted to the enveloping curve of the balancing shaft provided with a web.